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Controlled Switching of Multicomponent Heterocyclizations of 5‐Amino‐ N ‐arylpyrazole‐4‐carboxamides, 1,3‐Cyclohexanediones, and Aldehydes
Author(s) -
Chebanov Valentin A.,
Saraev Vyacheslav E.,
Shishkina Svetlana V.,
Shishkin Oleg V.,
Musatov Vladimir I.,
Desenko Sergey M.
Publication year - 2012
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201200669
Subject(s) - chemistry , dimethylformamide , catalysis , pyrazole , organic chemistry , medicinal chemistry , solvent
Multicomponent heterocyclization of 5‐amino‐ N ‐arylpyrazole‐4‐carboxamides, 1,3‐cyclohexanediones, and aromatic aldehydes was studied, and reaction conditions allowing selective switching between two directions were found. When the reaction was carried out under thermal heating or ultrasonication at room temperature, formation of linear pyrazoloquinoline‐3‐carboxamides was observed. Isomeric angular heterocycles were obtained by ultrasonic‐assisted synthesis at ambient temperature in the presence of HCl catalyst. Treatment with 2 equiv. of 1,3‐diketone in boiling N , N ‐dimethylformamide/HCl gave a mixture of pyrazoloquinoline‐3‐carboxamides and unusual acridin‐10‐yl‐pyrazole‐4‐carboxamides, which showed hindered rotation of the pyrazole fragment around the C–N bond.